Editor’s Note: This story was first published in November 2019.

CNN  — 

Remember when Princess Diana hit the dance floor at the White House with “Saturday Night Fever” star John Travolta?

It was November 1985, and the unlikely partners were guests of President Ronald Reagan and first lady Nancy Reagan.

He wore a slick black suit. She wore a midnight blue velvet gown by couturier Victor Edelstein with a sapphire and pearl choker, an outfit that has since become emblematic of the princess.

“There are three iconic images of Diana: this dress, the wedding dress, and the ‘revenge dress,’” said auctioneer Kerry Taylor in a 2019 interview, referring to the off-the-shoulder Christina Stambolian dress Diana wore the night Prince Charles publicly acknowledged his infidelity.

The blue Edelstein gown went under the hammer in 2019 at Kerry Taylor Auctions, where it was expected to fetch up to £350,000 (about $388,000).

Instead, the dress was sold outside of the auction for £264,000 ($347,000) to Historic Royal Palaces (HRP), an independent charity that looks after palaces in the UK. It last sold in March 2013 at the same auction house for £240,000 ($311,000) to a British buyer who bought the dress as a gift for his wife, Taylor said.

Taylor believes interest in the dress has remained not only because it belonged to Diana but because of the moment it represents.

“Here was this beautiful young woman, dancing with this Hollywood star. She was in awe of him, he was in awe of her. Two beautiful young people, carefree, dancing with the eyes of the world upon them.”

That evening, Charles and Diana still appeared to represent the “fairytale” royal romance, Taylor explained. “So it became one of the most important moments for Diana in the public eye.”

Travolta called the moment he danced with Diana "one of the highlights of [his] life" in a 2016 interview.

Princess Diana and Prince Charles attended the White House dinner on the first night of their royal tour of the US, alongside famous guests including Travolta, Neil Diamond, Leontyne Price, Tom Selleck, Gloria Vanderbilt, Estée Lauder, Clint Eastwood and Mikhail Baryshnikov.

Diana personally requested the invitation of Travolta, Eastwood and Diamond, the Washington Post reported at the time. “I’m so nervous my stomach is all butterflies,” Diamond told the newspaper. “I’d rather face an audience of 20,000.”

Travolta later told ABC News that it was one of the highlights of his life.

After Diana and Charles divorced in August 1996, Diana renounced some of the glamour of her royal life as she intensified her focus on humanitarian work.

In June 1997, two months before her death in a Paris car crash, she donated 79 elaborate gowns to be auctioned at Christie’s for charity – including the blue velvet Edelstein dress.

“Of course it is a wrench to let go of these beautiful dresses,” Diana told Vanity Fair. “However, I am extremely happy that others can now share the joy that I had wearing them.”

The magazine called the auction a “metamorphosis” for the Princess in an article titled “Diana Reborn,” opining, “She is jettisoning a life that never was.”

Of all the gowns, the Edelstein dress attracted the highest bids, selling for $222,500, a new record for garment sales at Christie’s, the New York Times reported.

The previous record of $145,000 had been set by none other than the polyester white suit Travolta wore in “Saturday Night Fever.”

Taylor initially expected an American buyer to win the dress. “This dress is huge in America,” she said.

“She wore it at the White House with the Reagans, so for an American collector, this is the key piece.”

But, in the end, a spokeswoman for the auction house noted that the seller was happy the dress is staying in the UK.

“We’re delighted to have acquired this iconic evening gown for the Royal Ceremonial Dress Collection – a designated collection of national and international importance – over twenty years since it first left Kensington Palace,” said Eleri Lynn, curator at HRP, in a statement in December.

“Not only is the ‘Travolta’ dress a fantastic example of couture tailoring designed to dazzle on a state occasion, it represents a key moment in the story of twentieth century royal fashion.”

It’s likely to be a good investment, too. “There’s still a huge interest in Princess Diana which cuts across all age groups,” Taylor added. “The interest in the princess is increasing, not declining.”

CNN’s Jack Guy contributed to this report.